From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.167.197 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792708421; b=oQ3IMliULpfdp8tGX4xc9oSj4btJSfBtkHe75PVKulm+kIwFaqRgcjxNy0ANptMX4okR sj6LQK+FKdAxDgqzPvWS+ZpRkeS0tq50iXn5PRMxWfs3Kfc3gIPC3K4ieEZXLkJVWlu3D RpXWT7iSWTHb+HkftiYtzBdAFlrq2y4n8lXNv4cvVHXqSc0jlV7MaCG0Ic0Cw50NNwKKX KmQAa71N6Rbvq48gsNWTRQ1lYyl9zMX1KbNafupPYvKUOzAyVWv1UGGP3I2NLcubZhXda lCWtFotlOyiXJ/DYcfz/5IaD0RmXkZdODNbXcuScrvUzQ8+MTURpCUzfgmGCI/isTxw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792708421; h=DMARC-Filter:Received:X-Google-DKIM-Signature:X-Forwarded-Encrypted: X-Gm-Message-State:MIME-Version:X-Received:Date: X-Google-Appengine-App-Id:X-Google-Appengine-App-Id-Alias:Message-ID: Subject:From:To:Content-Type; bh=2YhGmICq4X0jtn4PR3OTh5SkzrcHalK2T3Oao0NE/oU=; b=pAPMAqyEdVzyTMX+OhnGFT65w+EEfGRInzCuvyK1w0IIDfeVaFK6aYUc4tt0vvPmwALu 7vzxaTNA8Xklu+NtPwDGqGcpEybgNzDUNiNbu2Pz3QI3KoDWkmuiGFDSbTk+ASe5n0Cfn LsFqoTNLtegUyej9XV4hU9kaBMMfolQwAfeHwTs0tP5q1muVwVBE89OxEszCtyZaCTXm4 ifQeH5rsPmFRn11JWeTYmYM+ny5StgHy4rDYLkPM8L0HYsGRsZvRX+kNK2NCA/1Wp5jJK Ctus/Lus+C3SN1JSCRktKgyuV1LvvfoVScyhZc86XVlqgM5BzRxP2414+QlFVf/rkPA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.remote-ip=209.85.167.197 Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE2CB606A319 for ; Thu, 22 Oct 2026 22:33:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org BE2CB606A319 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oi1-f197.google.com with SMTP id 5614622812f47-4f9b643ae53so311332b6e.3 for ; Thu, 22 Oct 2026 15:33:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792708420; x=1793313220; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=2YhGmICq4X0jtn4PR3OTh5SkzrcHalK2T3Oao0NE/oU=; b=lHtA1b8RUQVuud+WuFfFqKdgrGr4N6Lwf4zvt9DLc0PPaJmU30X7zvs8S7WFE7r8Qk TYlafaL1lCtHv+lEFUiAbtrbkmEBnKEZ+IfvoLdKHODmulwT7wBHwcBmQeWoiwNSfxCm FrfCRA06sJKMXzOtYTj801upctT+09MtpYyqyr8upaL6jGwMEUiKyEhQtex+/XMp/GKw PkADhknFjiPrgvtD5ALXIXUVUhdlr99AHFBkZ/qDngJvNe8dqWPK5Xeyuc48mKYZqojy bg2Z6uVB2rhUC/2OQ6Qq2yP7TIQ7EScTeORdJHSYEI5OC3fCLglwKNwvo6vKlALw333c Lqsw== X-Forwarded-Encrypted: i=1; AKwUvBw7evgDGbsrWoIF37z+rqY05iuULfrX+6pSrQ7NqL65OvPcwpY7joyMCFQZY1UtzEyGnGx+OftYnrtmORs=@vger.kernel.org X-Gm-Message-State: AFq9FYLMIKbVxfBISUGD16T37GpAM811UeRsDfcZNjmJnZ+xK5of+WYc dXC5/+2WUrYhZQwwnQEtRBeeafVzfc+dsyNgTZUpSumgfCSlpg7NPEiSBFnJAtTfRCKv3wC3zEH xNziHOTu8Cm+XLE0xUJUwoMUmGhK4A911HYyixiK6AyElZ12p3dVoL4UxA3g= X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Received: by 2002:a05:6808:1209:b0:4c4:9f7e:92ce with SMTP id 5614622812f47-55be85c1e6fmr338343b6e.38.1792708419882; Thu, 22 Oct 2026 15:33:39 -0700 (PDT) Date: Thu, 22 Oct 2026 15:33:39 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6ada8f43.d1c214cc.659fa.00e0.GAE@google.com> Subject: [syzbot] [fs?] possible deadlock in v2_write_dquot From: syzbot To: jack@suse.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: a0ff06b3a7bd Merge tag 'firewire-fixes-7.3-final' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13a993a9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=c4b098695335c89f dashboard link: https://syzkaller.appspot.com/bug?extid=75d986c18cef4710fc85 compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/2a3b826702d4/disk-a0ff06b3.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/6b5a43d8b46c/vmlinux-a0ff06b3.xz kernel image: https://storage.googleapis.com/syzbot-assets/3a84903a147f/bzImage-a0ff06b3.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+75d986c18cef4710fc85@syzkaller.appspotmail.com EXT4-fs (loop5): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback. ext4 filesystem being mounted at /1334/file0 supports timestamps until 2038-01-19 (0x7fffffff) ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Tainted: G L ------------------------------------------------------ syz.5.7752/28220 is trying to acquire lock: ffff8880535c6248 (&s->s_dquot.dqio_sem){++++}-{4:4}, at: v2_write_dquot+0xab/0x260 fs/quota/quota_v2.c:367 but task is already holding lock: ffff88805537bca0 (&dquot->dq_lock){+.+.}-{4:4}, at: dquot_acquire+0x67/0x620 fs/quota/dquot.c:486 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #9 (&dquot->dq_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 wait_on_dquot fs/quota/dquot.c:357 [inline] dqget+0x69d/0xbd0 fs/quota/dquot.c:997 __dquot_initialize+0x3c8/0xd40 fs/quota/dquot.c:1462 __ext4_new_inode+0x7ed/0x3ec0 fs/ext4/ialloc.c:1004 ext4_xattr_inode_create fs/ext4/xattr.c:1494 [inline] ext4_xattr_inode_lookup_create+0xb1e/0x1d70 fs/ext4/xattr.c:1604 ext4_xattr_block_set+0x223/0x29a0 fs/ext4/xattr.c:1924 ext4_xattr_set_handle+0xed9/0x15f0 fs/ext4/xattr.c:2461 ext4_xattr_set+0x257/0x340 fs/ext4/xattr.c:2563 __vfs_setxattr+0x442/0x480 fs/xattr.c:223 __vfs_setxattr_noperm+0x12a/0x660 fs/xattr.c:257 vfs_setxattr+0x163/0x360 fs/xattr.c:344 do_setxattr fs/xattr.c:662 [inline] filename_setxattr+0x296/0x630 fs/xattr.c:690 path_setxattrat+0x408/0x450 fs/xattr.c:734 __do_sys_setxattr fs/xattr.c:768 [inline] __se_sys_setxattr fs/xattr.c:764 [inline] __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:764 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #8 (&ei->xattr_sem){++++}-{4:4}: down_write+0x96/0x200 kernel/locking/rwsem.c:1631 ext4_write_lock_xattr fs/ext4/xattr.h:152 [inline] ext4_inline_data_truncate+0x1cf/0xbd0 fs/ext4/inline.c:1882 ext4_truncate+0x444/0x1110 fs/ext4/inode.c:4650 ext4_setattr+0x1147/0x1df0 fs/ext4/inode.c:6220 notify_change+0xbba/0xea0 fs/attr.c:556 do_truncate+0x1c2/0x250 fs/open.c:68 handle_truncate fs/namei.c:4300 [inline] do_open fs/namei.c:4840 [inline] path_openat+0x185e/0x2090 fs/namei.c:4999 do_file_open+0x23e/0x4a0 fs/namei.c:5028 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_creat fs/open.c:1501 [inline] __se_sys_creat fs/open.c:1495 [inline] __x64_sys_creat+0x8f/0xc0 fs/open.c:1495 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #7 (mapping.invalidate_lock#2){++++}-{4:4}: down_read+0x4a/0x330 kernel/locking/rwsem.c:1574 filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline] do_page_cache_ra mm/readahead.c:347 [inline] page_cache_ra_order+0xb37/0xee0 mm/readahead.c:558 do_sync_mmap_readahead+0x75e/0x990 mm/filemap.c:3443 filemap_fault+0x7d9/0x13b0 mm/filemap.c:3597 __do_fault+0x138/0x2a0 mm/memory.c:5565 do_read_fault mm/memory.c:6000 [inline] do_fault mm/memory.c:6134 [inline] do_pte_missing+0x2215/0x34b0 mm/memory.c:4700 handle_pte_fault mm/memory.c:6558 [inline] __handle_mm_fault mm/memory.c:6707 [inline] handle_mm_fault+0x1a53/0x3750 mm/memory.c:6876 do_user_addr_fault+0x746/0x1340 arch/x86/mm/fault.c:1394 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:141 [inline] copy_from_user_iter lib/iov_iter.c:67 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] __copy_from_iter lib/iov_iter.c:261 [inline] _copy_from_iter+0x216/0x1660 lib/iov_iter.c:272 copy_from_iter include/linux/uio.h:228 [inline] copy_from_iter_full include/linux/uio.h:245 [inline] skb_do_copy_data_nocache include/net/sock.h:2329 [inline] skb_copy_to_page_nocache include/net/sock.h:2355 [inline] tcp_sendmsg_locked+0x20cf/0x5400 net/ipv4/tcp.c:1310 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1451 sock_sendmsg_nosec+0x10e/0x180 net/socket.c:801 __sock_sendmsg net/socket.c:815 [inline] sock_write_iter+0x2de/0x3e0 net/socket.c:1266 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (sk_lock-AF_INET){+.+.}-{0:0}: lock_sock_nested+0x41/0x100 net/core/sock.c:3837 lock_sock include/net/sock.h:1713 [inline] inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:913 nbd_mark_nsock_dead+0x2cb/0x550 drivers/block/nbd.c:319 recv_work+0x1cee/0x1e10 drivers/block/nbd.c:1030 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #5 (&nsock->tx_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 nbd_handle_cmd drivers/block/nbd.c:1143 [inline] nbd_queue_rq+0x373/0xff0 drivers/block/nbd.c:1207 blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2130 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_work_fn+0x16c/0x300 block/blk-mq.c:2545 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #4 (&cmd->lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 nbd_queue_rq+0xc1/0xff0 drivers/block/nbd.c:1199 blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2130 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_work_fn+0x16c/0x300 block/blk-mq.c:2545 process_one_work kernel/workqueue.c:3396 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560 kthread+0x38b/0x480 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #3 (set->srcu){.+.+}-{0:0}: srcu_lock_sync include/linux/srcu.h:210 [inline] __synchronize_srcu+0xc9/0x2f0 kernel/rcu/srcutree.c:1462 elevator_switch+0x1e8/0x7b0 block/elevator.c:576 elevator_change+0x2fa/0x480 block/elevator.c:681 elevator_set_default+0x375/0x440 block/elevator.c:754 blk_register_queue+0x3f3/0x4e0 block/blk-sysfs.c:992 __add_disk+0x6b8/0xdb0 block/genhd.c:531 add_disk_fwnode+0x100/0x3a0 block/genhd.c:600 add_disk include/linux/blkdev.h:798 [inline] nbd_dev_add+0x733/0xb60 drivers/block/nbd.c:2026 nbd_init+0x168/0x1f0 drivers/block/nbd.c:2743 do_one_initcall+0x250/0x870 init/main.c:1362 do_initcall_level+0x10a/0x1a0 init/main.c:1424 do_initcalls+0x59/0xa0 init/main.c:1440 kernel_init_freeable+0x29d/0x3e0 init/main.c:1675 kernel_init+0x22/0x1d0 init/main.c:1565 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (&q->elevator_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821 elevator_change+0x1af/0x480 block/elevator.c:679 elv_iosched_store+0x504/0x630 block/elevator.c:826 queue_attr_store+0x207/0x2b0 block/blk-sysfs.c:906 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x612/0xba0 fs/read_write.c:687 ksys_write+0x150/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->q_usage_counter(io)#17){++++}-{0:0}: bio_queue_enter block/blk.h:95 [inline] blk_mq_submit_bio+0x7a7/0x2bb0 block/blk-mq.c:3138 __submit_bio_noacct_mq block/blk-core.c:756 [inline] submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790 __ext4_read_bh fs/ext4/super.c:181 [inline] ext4_read_bh+0x182/0x230 fs/ext4/super.c:206 ext4_bread+0x12d/0x180 fs/ext4/inode.c:1060 ext4_quota_read+0x189/0x390 fs/ext4/super.c:7397 read_blk fs/quota/quota_tree.c:61 [inline] find_tree_dqentry+0x1fc/0x1090 fs/quota/quota_tree.c:671 find_tree_dqentry+0x6c0/0x1090 fs/quota/quota_tree.c:698 find_tree_dqentry+0x6c0/0x1090 fs/quota/quota_tree.c:698 find_tree_dqentry+0x6c0/0x1090 fs/quota/quota_tree.c:698 find_dqentry fs/quota/quota_tree.c:716 [inline] qtree_read_dquot+0x5ac/0x8a0 fs/quota/quota_tree.c:736 v2_read_dquot+0x117/0x1d0 fs/quota/quota_v2.c:344 dquot_acquire+0x183/0x620 fs/quota/dquot.c:489 ext4_acquire_dquot+0x2f0/0x4e0 fs/ext4/super.c:7075 dqget+0x725/0xbd0 fs/quota/dquot.c:1002 __dquot_initialize+0x33a/0xd40 fs/quota/dquot.c:1462 ext4_rename fs/ext4/namei.c:3831 [inline] ext4_rename2+0x758/0x3270 fs/ext4/namei.c:4218 vfs_rename+0xbd9/0xef0 fs/namei.c:6207 filename_renameat2+0x533/0x9a0 fs/namei.c:6325 __do_sys_renameat2 fs/namei.c:6354 [inline] __se_sys_renameat2+0x5a/0x2c0 fs/namei.c:6349 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&s->s_dquot.dqio_sem){++++}-{4:4}: check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 down_write+0x96/0x200 kernel/locking/rwsem.c:1631 v2_write_dquot+0xab/0x260 fs/quota/quota_v2.c:367 dquot_acquire+0x328/0x620 fs/quota/dquot.c:498 ext4_acquire_dquot+0x2f0/0x4e0 fs/ext4/super.c:7075 dqget+0x725/0xbd0 fs/quota/dquot.c:1002 dquot_set_dqblk+0x2b/0xfd0 fs/quota/dquot.c:2777 quota_setquota+0x4e0/0x590 fs/quota/quota.c:310 __do_sys_quotactl fs/quota/quota.c:961 [inline] __se_sys_quotactl+0x2cc/0x9f0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &s->s_dquot.dqio_sem --> &ei->xattr_sem --> &dquot->dq_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&dquot->dq_lock); lock(&ei->xattr_sem); lock(&dquot->dq_lock); lock(&s->s_dquot.dqio_sem); *** DEADLOCK *** locks held by syz.5.7752/28220: 2, last CPU#0: #0: ffff8880535c60e8 (&type->s_umount_key#33){++++}-{4:4}, at: __super_lock fs/super.c:62 [inline] #0: ffff8880535c60e8 (&type->s_umount_key#33){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:124 #1: ffff88805537bca0 (&dquot->dq_lock){+.+.}-{4:4}, at: dquot_acquire+0x67/0x620 fs/quota/dquot.c:486 stack backtrace: CPU: 0 UID: 0 PID: 28220 Comm: syz.5.7752 Tainted: G L syzkaller #0 PREEMPT(lazy) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219 check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 down_write+0x96/0x200 kernel/locking/rwsem.c:1631 v2_write_dquot+0xab/0x260 fs/quota/quota_v2.c:367 dquot_acquire+0x328/0x620 fs/quota/dquot.c:498 ext4_acquire_dquot+0x2f0/0x4e0 fs/ext4/super.c:7075 dqget+0x725/0xbd0 fs/quota/dquot.c:1002 dquot_set_dqblk+0x2b/0xfd0 fs/quota/dquot.c:2777 quota_setquota+0x4e0/0x590 fs/quota/quota.c:310 __do_sys_quotactl fs/quota/quota.c:961 [inline] __se_sys_quotactl+0x2cc/0x9f0 fs/quota/quota.c:917 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffb1039e559 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffb11205028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3 RAX: ffffffffffffffda RBX: 00007ffb10625fa0 RCX: 00007ffb1039e559 RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffff80000801 RBP: 00007ffb10435ab8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000100 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffb10626038 R14: 00007ffb10625fa0 R15: 00007fff0c429e18 --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup